If you Option-double click an event in your iCal calendar, it highlights the event's title immediately and lets you edit it, without bringing up the pop-up window. Not necessarily faster, but less intrusive.

Thanks a lot!
I already began to hate leopard for having me clicking all the time. I prefer the way Tiger's iCal used to manage keyboard commands.
Is there a way to easily alter the time, date and other issues by shortcuts?

Use the Tab key to go to the event (it will visit every event in the view you are currently in; use Command-Right or Command-Left to switch current day/week/month), then Command-E to edit it. Not exactly efficient especially if you're in month view and have a lot of events, but it works.